Centella asiatica extract protects against amyloid ß1-40-induced neurotoxicity in neuronal cells by activating the antioxidative defence system.

Centella asiatica ( léi gong gen) is a traditional medicinal herb with high antioxidant activity, which decreases amyloid-ß (Aß) deposition in the brain. At the same time, aggregated Aß-induced oxidative stress is the trigger in the pathogenesis of Alzheimer's disease (AD). Here, we investigated the ability of C. asiatica ethanol extract (CAE) to protect PC12 and IMR32 cells from Aß1-40-induced production of reactive oxygen species (ROS) and concomitant neurotoxicity. Aggregated Aß1-40 treatment resulted in reduced cell viability, which can be reversed by cotreatment with 25, 50, and 100 µg/mL CAE. Moreover, CAE eliminated the Aß1-40-mediated increase in ROS production. Thus, CAE-mediated protection against aggregated Aß1-40-induced neurotoxicity is attributable to modulation of the antioxidative defense system in cells, including the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and levels of glutathione and glutathione disulfide by CAE. This emphasizes the potential therapeutic and preventive value of CAE in the treatment of AD.

Coenzyme Q0 from Antrodia cinnamomea in Submerged Cultures Induces Reactive Oxygen Species-Mediated Apoptosis in A549 Human Lung Cancer Cells.

We investigated the anticancer effects of Antrodia cinnamomea, a medicinal mushroom from Taiwan, on A549 human lung cancer cells using the ethyl acetate extract from submerged culture filtrates. Our results showed that 2,3-dimethoxy-5-methyl-1,4-benzoquinone (coenzyme Q0; CoQ0) derived from A. cinnamomea submerged culture filtrates has anticancer activity. CoQ0 treatment reduced the viability of A549, HepG2, and SW480 cancer cell lines. Furthermore, CoQ0 induced reactive oxygen species (ROS) generation and apoptosis in A549 cells, which was inhibited by the antioxidant ascorbic acid. To our knowledge, these data demonstrate for the first time that CoQ0 derived from A. cinnamomea submerged culture filtrates exerts its anticancer effect through the induction of ROS-mediated apoptosis in A549 human lung cancer cells.

Activation of antitumor immune responses by Ganoderma formosanum polysaccharides in tumor-bearing mice.

Fungi of the genus Ganoderma are basidiomycetes that have been used as traditional medicine in Asia and have been shown to exhibit various pharmacological activities. We recently found that PS-F2, a polysaccharide fraction purified from the submerged culture broth of Ganoderma formosanum, stimulates the maturation of dendritic cells and primes a T helper 1 (Th1)-polarized adaptive immune response in vivo. In this study, we investigated whether the immune adjuvant function of PS-F2 can stimulate antitumor immune responses in tumor-bearing mice. Continuous intraperitoneal or oral administration of PS-F2 effectively suppressed the growth of colon 26 (C26) adenocarcinoma, B16 melanoma, and sarcoma 180 (S180) tumor cells in mice without adverse effects on the animals' health. PS-F2 did not cause direct cytotoxicity on tumor cells, and it lost the antitumor effect in mice with severe combined immunodeficiency (SCID). CD4(+) T cells, CD8(+) T cells, and serum from PS-F2-treated tumor-bearing mice all exhibited antitumor activities when adoptively transferred to naïve animals, indicating that PS-F2 treatment stimulates tumor-specific cellular and humoral immune responses. These data demonstrate that continuous administration of G. formosanum polysaccharide PS-F2 can activate host immune responses against ongoing tumor growth, suggesting that PS-F2 can potentially be developed into a preventive/therapeutic agent for cancer immunotherapy.

Ganoderma formosanum polysaccharides attenuate Th2 inflammation and airway hyperresponsiveness in a murine model of allergic asthma.

Allergic asthma is an inflammatory disease of the airways mediated by Th2 immune responses and characterized by airway hyperresponsiveness (AHR). Fungi of the genus Ganoderma are basidiomycetes that have been used in traditional Asian medicine for centuries. We recently found that PS-F2, a polysaccharide fraction purified from the submerged culture broth of Ganoderma formosanum, stimulates the activation of dendritic cells and primes a T helper 1 (Th1)-polarized adaptive immune response. This study was designed to investigate whether the Th1 adjuvant properties of PS-F2 could suppress the development of allergic asthma in a mouse model. BALB/c mice were sensitized by repeated immunization with chicken ovalbumin (OVA) and alum, followed by intranasal challenge of OVA to induce acute asthma. PS-F2 administration during the course of OVA sensitization and challenge effectively prevented AHR development, OVA-specific IgE and IgG1 production, bronchial inflammation, and Th2 cytokine production. Our data indicate that PS-F2 has a potential to be used for the prevention of allergic asthma.

Polysaccharides from Ganoderma formosanum function as a Th1 adjuvant and stimulate cytotoxic T cell response in vivo.

The fungus of Ganoderma is a basidiomycete that possesses a variety of pharmacological effects and has been used in traditional Asian medicine for centuries. Ganoderma formosanum is a native Ganoderma species isolated in Taiwan, and we have previously demonstrated that PS-F2, a polysaccharide fraction purified from the submerged culture broth of G. formosanum, exhibits immunostimulatory properties in macrophages. In this study, we further characterized the adjuvant functions of PS-F2. In vitro, PS-F2 stimulated dendritic cells (DCs) to produce proinflammatory cytokines, including TNF-α, interleukin (IL)-6, and IL-12/IL-23 p40. PS-F2 also stimulated DCs to express the maturation markers CD40, CD80, CD86, and MHC class II. In a murine splenocyte culture, PS-F2 treatment resulted in elevated expression of T-bet and interferon (IFN)-γ in T lymphocytes. When used as an adjuvant in vivo with the ovalbumin (OVA) antigen, PS-F2 stimulated OVA-specific antibody production and primed IFN-γ production in OVA-specific T lymphocytes. PS-F2-adjuvated immunization also induced OVA-specific CTLs, which protected mice from a challenge with tumor cells expressing OVA. Collectively, our data show that PS-F2 functions as an adjuvant capable of inducing a Th1-polarized adaptive immune response, which would be useful in vaccines against viruses and tumors.

Extracellular polysaccharides produced by Ganoderma formosanum stimulate macrophage activation via multiple pattern-recognition receptors.

BACKGROUND: The fungus of Ganoderma is a traditional medicine in Asia with a variety of pharmacological functions including anti-cancer activities. We have purified an extracellular heteropolysaccharide fraction, PS-F2, from the submerged mycelia culture of G. formosanum and shown that PS-F2 exhibits immunostimulatory activities. In this study, we investigated the molecular mechanisms of immunostimulation by PS-F2. RESULTS: PS-F2-stimulated TNF-α production in macrophages was significantly reduced in the presence of blocking antibodies for Dectin-1 and complement receptor 3 (CR3), laminarin, or piceatannol (a spleen tyrosine kinase inhibitor), suggesting that PS-F2 recognition by macrophages is mediated by Dectin-1 and CR3 receptors. In addition, the stimulatory effect of PS-F2 was attenuated in the bone marrow-derived macrophages from C3H/HeJ mice which lack functional Toll-like receptor 4 (TLR4). PS-F2 stimulation triggered the phosphorylation of mitogen-activated protein kinases JNK, p38, and ERK, as well as the nuclear translocation of NF-κB, which all played essential roles in activating TNF-α expression. CONCLUSIONS: Our results indicate that the extracellular polysaccharides produced by G. formosanum stimulate macrophages via the engagement of multiple pattern-recognition receptors including Dectin-1, CR3 and TLR4, resulting in the activation of Syk, JNK, p38, ERK, and NK-κB and the production of TNF-α.

Mapping of IgE and IgG4 antibody-binding epitopes in Cyn d 1, the major allergen of Bermuda grass pollen.

BACKGROUND: Bermuda grass pollen (BGP) is an important seasonal aeroallergen worldwide which induces allergic disorders such as allergic rhinitis, conjunctivitis and asthma. Cyn d 1 is the major allergen of BGP. This study is aimed to map human IgE and IgG(4) antibody-binding sequential epitopes on Cyn d 1 by dot immunoblotting. METHODS: Synthetic peptides (10-mers; 5 overlapping residues) spanning the full length of Cyn d 1 were used for dot immunoblotting to map human IgE and IgG(1-4) antibody-binding regions with sera from BGP-allergic patients. Synthetic peptides with more overlapping residues were used for further mapping. Essential amino acids in each epitope were examined by single amino acid substitution with alanine. Peptides with sequence polymorphism of epitopes of Cyn d 1 were also synthesized to extrapolate their differences in binding capability. RESULTS: Four major IgE-binding epitopes (peptides 15(-1), 21, 33(-2) and 35(+1), corresponding to amino acids 70-79, 101-110, 159-167 and 172-181) and 5 major IgG(4)-binding epitopes (peptides 15(-1), 30(-2), 33(-2), 35(+1) and 39, corresponding to amino acids 70-79, 144-153, 159-167, 172-181 and 192-200) were identified. They are all located on the surface of the simulated Cyn d 1 molecule, and three of them are major epitopes for both IgE and IgG(4). Their critical amino acids were all characterized. Major epitopes for human IgG(1) to IgG(4) are almost identical. CONCLUSIONS: This is the first study to map the sequential epitopes for human IgE and IgG(4) subclasses in Cyn d 1. It will be helpful for future development in immunotherapy and diagnosis.

1-(3,4-dimethoxyphenyl)-3,5-dodecenedione (I6) induces G1 arrest and apoptosis in human promyelocytic leukemia HL-60 cells.

1-(3,4-dimethoxyphenyl)-3,5-dodecenedione (I6), a gingerdione derivative, was synthesized in our laboratory, has been demonstrated to be an effective anti-tumor agent in human leukemia cells. Gingerdione is one of the components from ginger. In the present study, we found that I6 could inhibit cell proliferation in the time- and dose-dependent manner in human promyelocytic leukemia HL-60 cells. To investigate the anti-proliferation mechanism of I6, cell cycle analysis was performed. Results showed that I6 induced significant G1 arrest and apoptosis in HL-60 cells. It was proved by the reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of regulatory on G1 arrest that the levels of p15 and p27 increased after treatment and mRNA levels of cyclin D2, cyclin E, and cdc25A were decreased. The I6-induced apoptosis was further confirmed by DNA fragmentation assay. The DNA gel electrophoresis showed that I6 induced DNA fragmentation, a biochemical hallmark of apoptosis, in HL-60 cells. I6-induced apoptosis was accompanied by an apparent up-regulation of caspase-3, and down-regulation of Bcl-2. Taken together, these results suggest that markedly down-regulation of G1 associated cyclin D2, cyclin E and cdc25A and up-regulation of CDKI, p15 and p27, and may contribute to I6-mediated cell cycle arrest. Furthermore, the Bcl-2 expression decrease and caspase-3 activation may be the plausible mechanism by which I6 induced apoptosis. These results suggest that I6 is a potent anti-HL-60 drug and possess a significant action on cell cycle before commitment for apoptosis occurrence.